Sir,

Sympathetic ophthalmia (SO) is thought to be an autoimmune reaction to retinal antigens exposed to conjuctival or orbital lymphatics. A study by the British Ophthalmic Surveillance Unit estimated the incidence of SO as 0.3/100 000, identifying 23 new cases in a 15 month period, with a history of ocular surgery, commonly retinal, or trauma in all cases.1 One theory of pathogenesis suggests that concurrent infection of ocular tissue provokes an immune response involving exposed retinal antigens, thus inciting an autoimmune reaction.2, 3 SO is much more likely after traumatic globe penetration (0.19%) than intraocular surgery (0.007%),4 and the higher incidence of concurrent infection may in part explain this difference. We present a case of SO developing after contralateral fungal infection, in the absence of penetrating trauma.

Case report

A 16-year-old male apprentice roofer sustained a corneal foreign body at work. He developed an aggressive Aspergillus fumigatus keratitis, which involved the limbus and required 8 weeks' intensive antifungal treatment (Figure 1). Three weeks later the sudden onset of pain heralded a central corneal perforation. Three days later the eye was eviscerated.

Figure 1
figure 1

Severe fungal keratitis in the left eye, involving the limbus.

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Eighteen days later he presented with pain, blurred vision, and photophobia in his fellow eye. Visual acuity was 6/12, with nongranulomatous anterior uveitis. Funduscopy revealed peripheral white retinal nodules (Figure 2). Histological examination of the evisceration specimen confirmed SO, with noncaseating granulomas, profound lymphocytic infiltration, numerous eosinophils in the choroid (Figure 3), and Dalen-Fuchs nodules. Treatment with high-dose oral and topical corticosteroids suppressed the intraocular inflammation. After 6 months the eye remains quiet, with a visual acuity of 6/4, using prednisolone 7.5 mg daily.

Figure 2
figure 2

The right fundal midperiphery, showing multifocal infiltrates and patchy mild retinal vasculitis.

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Figure 3
figure 3

Histology of left evisceration specimen. There is a profound lymphocytic infiltration of the choroid, and there are confluent noncaseating epithelioid granulomata. Eosinophils are numerous, and some epithelioid cells contain melanin granules (H&E × 10 original magnification).

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Comment

development of SO in the absence of preceding trauma or surgery is very rare. In a series of 105 cases, Lubin et al2 found that 6% followed spontaneous perforation of corneal ulcers and a further case with antecedent adherent leucoma has been described,5 but these spontaneous perforations were precursor events. SO has been reported on several occasions following cyclodestructive procedures,6 but almost all patients had previously undergone intraocular surgery. Malignant melanoma has been associated with SO, either primarily (albeit in association with spontaneous perforation7) or following irradiation and nonpenetrating surgery.8 A blunt injury with hyphaema also led to SO.9

In our case, characteristic histological changes of SO were confirmed in the evisceration specimen. These changes, particularly the development of epithelioid granulomata, probably could not have occurred in the 3-day period between spontaneous perforation and evisceration, therefore preceded it.

We hypothesise that this chronic severe infection, with limbal involvement, allowed the diffusion of intraocular fungal antigens and proinflammatory mediators which allowed access through a disturbed blood-retinal barrier to expose retinal antigens and allow the development of SO. Fungal antigens may have played an adjuvant role in its development.